I heard recently that we should not discuss new theories here. Why we should not discuss new theories when they are very closely resembling the existing accepted theories but with slight modification. After all even if we fail with new theory, we end up learing the old established theory in a better way.
I'd say the key point emerges in your comment above:
is there any physics forum to discuss new theories
This is not a discussion forum - it is a question and answer site. It's hard to see how you could ask a question about a new theory without it turning into a discussion. That doesn't mean we hate and revile speculation, just that this isn't the place for it.
I must admit I'm a bit uncomfortable with the phrase "non-mainstream physics" because I'm sure that's how Pope Urban VIII would have described Galileo. Actually I think the wording on the vote to close dialog is pretty good when it says:
Questions about the general correctness of unpublished personal theories are off topic, although specific questions evaluating new theories in the context of established science are usually allowed.